Grease compositions having polyurea thickeners made with isocyanate terminated prepolymers

Abstract

This disclosure relates to grease compositions having at least one base oil, and at least one polyurea thickener. The at least one polyurea thickener is prepared by reacting an isocyanate-terminated prepolymer with at least one amine under reaction conditions sufficient to prepare the at least one polyurea thickener. The isocyanate-terminated prepolymer is prepared by reacting a polyisocyanate with a polyol, at an NCO/OH equivalent ratio of 1.05:1 to 10:1, under reaction conditions sufficient to prepare said isocyanate-terminated prepolymer. When the grease compositions are used under high temperature conditions, structural stability and resistance to breaking down in accordance with DIN 51821 (FAG FE9) is improved. This disclosure also relates to a method of preparing the grease compositions. This disclosure further relates to a method for improving high temperature performance of a grease composition in a mechanical component lubricated with the grease composition.

1 . A grease composition comprising:
 at least one base oil; and   at least one polyurea thickener;
 wherein said at least one polyurea thickener is prepared by reacting an isocyanate-terminated prepolymer with at least one amine under reaction conditions sufficient to prepare said at least one polyurea thickener; and 
   wherein said isocyanate-terminated prepolymer is prepared by reacting a polyisocyanate with a polyol, at an NCO/OH equivalent ratio of 1.05:1 to 10:1, under reaction conditions sufficient to prepare said isocyanate-terminated prepolymer.   
     
     
         2 . The grease composition of  claim 1  wherein said isocyanate-terminated prepolymer has an isocyanate content of 0.5 to 40 weight percent, based on the weight of the isocyanate-terminated prepolymer after reaction. 
     
     
         3 . The grease composition of  claim 1  wherein the polyisocyanate is selected from the group consisting of 2,4-toluene diisocyanate (TDI); 2,6-toluene diisocyanate (TDI); 4,4′-diisocyanatodiphenylmethane (MDI); p-phenylene diisocyanate (PPDI); diphenyl-4,4′-diisocyanate; dibenzyl-4,4′-diisocyanate; stilbene-4,4′-diisocyanate; benzophenone-4,4′-diisocyanate; 1,3- and 1,4-xylene diisocyanate; and mixtures thereof. 
     
     
         4 . The grease composition of  claim 1  wherein the polyisocyanate is selected from the group consisting of 1,6-hexamethylene diisocyanate (HDI); 1,3-cyclohexyl diisocyanate; 1,4-cyclohexyl diisocyanate (CHDI); saturated diphenylmethane diisocyanate H(12)MDI; bis{4-isocyanatocyclohexyl}methane; 4,4′-methylene dicyclohexyl diisocyanate; 4,4-methylene bis (dicyclohexyl)diisocyanate; methylene dicyclohexyl diisocyanate; methylene bis (4-cyclohexylene isocyanate); saturated methylene diphenyl diisocyanate; saturated methyl diphenyl diisocyanate; isophorone diisocyanate (IPDI); hexamethylene diisocyanate (HDI); 2,2,4-trimethyl-1,6-hexamethylene diisocyanate 2,4,4-trimethyl-1,6-hexamethylene diisocyanate; dodecamethylene diisocyanate; 1,4-diisocyanatocyclohexane; 1-isocyanato-3,3,5-trimethy-5-isocyanatomethylcyclohexane (IPDI); 2,4′- and/or 4,4′-diisocyanato-dicyclohexyl methane; 2,4-diisocyanato-diphenyl methane; 4,4′-diisocyanato-diphenyl methane; 2,4-diisocyanatotoluene; 2,6-diisocyanatotoluene; and mixtures of these isomers with their higher homologues. 
     
     
         5 . The grease composition of  claim 1  wherein the polyisocyanate is selected from the group consisting of hexamethylene diisocyanate (HDI); 2,2,4-trimethyl-1,6-hexamethylene diisocyanates; 2,4,4-trimethyl-1,6-hexamethylene diisocyanate; dodecamethylene diisocyanate; 1,4-diisocyanatocyclohexane; 1-isocyanato-3,3,5-trimethy-5-isocyanatomethylcyclohexane; 2,4′-diisocyanato-dicyclohexyl methane; 4,4′-diisocyanato-dicyclohexyl methane; 2,4-diisocyanato-diphenyl methane; 4,4′-diisocyanato-diphenyl 2,4-diisocyanatotoluene; 2,6-diisocyanatotoluene; and any mixtures of these compounds and their higher homologues. 
     
     
         6 . The grease composition of  claim 1  wherein the polyol is selected from the group consisting of polyester polyols, polycaprolactone polyols, and polyether polyols. 
     
     
         7 . The grease composition of  claim 1  wherein the polyol is selected from the group consisting of polyester polyols, polycaprolactone polyols, polyether polyols, polyhydroxy polycarbonates, polyhydroxy polyacetals, polyhydroxy polyacrylates, polyhydroxy polyester amides and polyhydroxy polythioethers or mixtures thereof; wherein said polyols have at least two hydroxyl groups per molecule and have a hydroxyl group content of 0.5 to 20 weight percent. 
     
     
         8 . The grease composition of  claim 1  wherein the polyol is selected from the group consisting of polyester polyols, polycaprolactone polyols, polyether polyols, polytetramethylene ether glycol, polyhydroxy polycarbonates, polyhydroxy polyacetals, polyhydroxy polyacrylates, polyhydroxy polyester amides and polyhydroxy polythioethers, or mixtures thereof. 
     
     
         9 . The grease composition of  claim 1  wherein the isocyanate-terminated prepolymer is selected from the group consisting of TDI-ether, TDI-ester, TDI-lactone, MDI-ether, MDI-ester, MDI-lactone, H(12)MDI-ether, H(12)MDI-ester, H(12)MDI-lactone, HDI-ether, HDI-ester, HDI-lactone, IPDI-ether, IPDI-ester, IPDI-lactone, PPDI-ether, PPDI-ester, PPDI-lactone, and mixtures thereof. 
     
     
         10 . The grease composition of  claim 1  wherein the amine is selected from the group consisting of pentylamine, hexylamine, heptylamine, octylamine, decylamine, dodecylamine, tetradecylamine, hexadecylamine, octadecylamine, eicosylamine, dodecenylamine, hexadecenylamine, octadecenylamine, octadecadienylamine, abietylamine, aniline, toluidine, naphthylamine, cumylamine, bomylamine, fenchylamine, tertiary butyl aniline, benzylamine, β-phenethylamine, stearylamine, laurylamine, palmitylamine, oleylamine, petroselinylamine, linoleylamine, linolenylamine, eleostearylamine, cyclohexylamine, primary tallow amine, ethylenediamine, propanediamine, butanediamine, hexanediamine, dodecanediamine, octanediamine, hexadecanediamine, cyclohexanediamine, cyclooctanediamine, phenylenediamine, tolylenediamine, xylylenediamine, dianiline methane, ditoluidinemethane, bis(aniline), bis(toluidine), piperazine, and mixtures thereof. 
     
     
         11 . The grease composition of  claim 1  wherein, when used under high temperature conditions, high temperature performance in accordance with DIN 51821 (FAG FE9) is improved, as compared to high temperature performance achieved using a grease composition containing other than said polyurea thickener. 
     
     
         12 . The grease composition of  claim 1  wherein structural stability and resistance to breaking down is improved when tested under high temperature conditions in accordance with DIN 51821 (FAG FE9), as compared to structural stability and resistance to breaking down achieved using a grease composition containing other than said polyurea thickener. 
     
     
         13 . The grease composition of  claim 1  wherein, when tested using a Mini-Traction Machine (MTM) at 100° C., 1.0 GPa, 50% slide/roll ratio (SRR), and 3.0 m/s-0 m/s, coefficient of friction is improved, as compared to coefficient of friction achieved using a grease composition containing other than said polyurea thickener. 
     
     
         14 . The grease composition of  claim 1  wherein the at least one base oil comprises a Group I, Group II, Group III, Group IV, Group V base oil, and combinations thereof. 
     
     
         15 . The grease composition of  claim 1  further comprising at least one performance additive selected from the group consisting of an anticorrosive agent or corrosion inhibitor, an extreme pressure additive, an antiwear agent, a pour point depressants, an antioxidant or oxidation inhibitor, a rust inhibitor, a metal deactivator, a dispersant, a demulsifier, a dye or colorant/chromophoric agent, a seal compatibility agent, a friction modifier, a viscosity modifier/improver, a viscosity index improver, and combinations thereof. 
     
     
         16 . The grease composition of  claim 1  wherein the at least one base oil is present in an amount of from 50 to 95 weight percent, and the at least one polyurea thickener is present in an amount of from 0.5 to 20 weight percent, based on the total weight of the grease composition. 
     
     
         17 . A method of preparing a grease composition comprising mixing at least one base oil, and at least one polyurea thickener; wherein said at least one polyurea thickener is prepared by reacting an isocyanate-terminated prepolymer with at least one amine under reaction conditions sufficient to prepare said at least one polyurea thickener; and wherein said isocyanate-terminated prepolymer is prepared by reacting a polyisocyanate with a polyol, at an NCO/OH equivalent ratio of 1.05:1 to 10:1, under reaction conditions sufficient to prepare said isocyanate-terminated prepolymer. 
     
     
         18 . The method of  claim 17  wherein said isocyanate-terminated prepolymer has an isocyanate content of 0.5 to 40 weight percent, based on the weight of the isocyanate-terminated prepolymer after reaction. 
     
     
         19 . The method of  claim 17  wherein the polyisocyanate is selected from the group consisting of 2,4-toluene diisocyanate (TDI); 2,6-toluene diisocyanate (TDI); 4,4′-diisocyanatodiphenylmethane (MDI); p-phenylene diisocyanate (PPDI); diphenyl-4,4′-diisocyanate; dibenzyl-4,4′-diisocyanate; stilbene-4,4′-diisocyanate; benzophenone-4,4′-diisocyanate; 1,3- and 1,4-xylene diisocyanate; and mixtures thereof. 
     
     
         20 . The method of  claim 17  wherein the polyisocyanate is selected from the group consisting of 1,6-hexamethylene diisocyanate (HDI); 1,3-cyclohexyl diisocyanate; 1,4-cyclohexyl diisocyanate (CHDI); saturated diphenylmethane diisocyanate H(12)MDI; bis{4-isocyanatocyclohexyl}methane; 4,4′-methylene dicyclohexyl diisocyanate; 4,4-methylene bis (dicyclohexyl)diisocyanate; methylene dicyclohexyl diisocyanate; methylene bis (4-cyclohexylene isocyanate); saturated methylene diphenyl diisocyanate; saturated methyl diphenyl diisocyanate; isophorone diisocyanate (IPDI); hexamethylene diisocyanate (HDI); 2,2,4-trimethyl-1,6-hexamethylene diisocyanate 2,4,4-trimethyl-1,6-hexamethylene diisocyanate; dodecamethylene diisocyanate; 1,4-diisocyanatocyclohexane; 1-isocyanato-3,3,5-trimethy-5-isocyanatomethylcyclohexane (IPDI); 2,4′- and/or 4,4′-diisocyanato-dicyclohexyl methane; 2,4-diisocyanato-diphenyl methane; 4,4′-diisocyanato-diphenyl methane; 2,4-diisocyanatotoluene; 2,6-diisocyanatotoluene; and mixtures of these isomers with their higher homologues. 
     
     
         21 . The method of  claim 17  wherein the polyisocyanate is selected from the group consisting of hexamethylene diisocyanate (HDI); 2,2,4-trimethyl-1,6-hexamethylene diisocyanates; 2,4,4-trimethyl-1,6-hexamethylene diisocyanate; dodecamethylene diisocyanate; 1,4-diisocyanatocyclohexane; 1-isocyanato-3,3,5-trimethy-5-isocyanatomethylcyclohexane; 2,4′-diisocyanato-dicyclohexyl methane; 4,4′-diisocyanato-dicyclohexyl methane; 2,4-diisocyanato-diphenyl methane; 4,4′-diisocyanato-diphenyl 2,4-diisocyanatotoluene; 2,6-diisocyanatotoluene; and any mixtures of these compounds and their higher homologues. 
     
     
         22 . The method of  claim 17  wherein the polyol is selected from the group consisting of polyester polyols, polycaprolactone polyols, and polyether polyols. 
     
     
         23 . The method of  claim 17  wherein the polyol is selected from the group consisting of polyester polyols, polycaprolactone polyols, polyether polyols, polyhydroxy polycarbonates, polyhydroxy polyacetals, polyhydroxy polyacrylates, polyhydroxy polyester amides and polyhydroxy polythioethers or mixtures thereof; wherein said polyols have at least two hydroxyl groups per molecule and have a hydroxyl group content of 0.5 to 20 weight percent. 
     
     
         24 . The method of  claim 17  wherein the polyol is selected from the group consisting of polyester polyols, polycaprolactone polyols, polyether polyols, polytetramethylene ether glycol, polyhydroxy polycarbonates, polyhydroxy polyacetals, polyhydroxy polyacrylates, polyhydroxy polyester amides and polyhydroxy polythioethers, or mixtures thereof. 
     
     
         25 . The method of  claim 17  wherein the isocyanate-terminated prepolymer is selected from the group consisting of TDI-ether, TDI-ester, TDI-lactone, MDI-ether, MDI-ester, MDI-lactone, H(12)MDI-ether, H(12)MDI-ester, H(12)MDI-lactone, HDI-ether, HDI-ester, HDI-lactone, IPDI-ether, IPDI-ester, IPDI-lactone, PPDI-ether, PPDI-ester, PPDI-lactone, and mixtures thereof. 
     
     
         26 . The method of  claim 17  wherein the amine is selected from the group consisting of pentylamine, hexylamine, heptylamine, octylamine, decylamine, dodecylamine, tetradecylamine, hexadecylamine, octadecylamine, eicosylamine, dodecenylamine, hexadecenylamine, octadecenylamine, octadecadienylamine, abietylamine, aniline, toluidine, naphthylamine, cumylamine, bomylamine, fenchylamine, tertiary butyl aniline, benzylamine, β-phenethylamine, stearylamine, laurylamine, palmitylamine, oleylamine, petroselinylamine, linoleylamine, linolenylamine, eleostearylamine, cyclohexylamine, primary tallow amine, ethylenediamine, propanediamine, butanediamine, hexanediamine, dodecanediamine, octanediamine, hexadecanediamine, cyclohexanediamine, cyclooctanediamine, phenylenediamine, tolylenediamine, xylylenediamine, dianiline methane, ditoluidinemethane, bis(aniline), bis(toluidine), piperazine, and mixtures thereof. 
     
     
         27 . The method of  claim 17  wherein, when used under high temperature conditions, high temperature performance in accordance with DIN 51821 (FAG FE9) is improved, as compared to high temperature performance achieved using a grease composition containing other than said polyurea thickener. 
     
     
         28 . The method of  claim 17  wherein structural stability and resistance to breaking down is improved when tested under high temperature conditions in accordance with DIN 51821 (FAG FE9), as compared to structural stability and resistance to breaking down achieved using a grease composition containing other than said polyurea thickener. 
     
     
         29 . The method of  claim 17  wherein, when tested using a Mini-Traction Machine (MTM) at 100° C., 1.0 GPa, 50% slide/roll ratio (SRR), and 3.0 m/s-0 m/s, coefficient of friction is improved, as compared to coefficient of friction achieved using a grease composition containing other than said polyurea thickener. 
     
     
         30 . The method of  claim 17  wherein the at least one base oil comprises a Group I, Group II, Group III, Group IV, Group V base oil, and combinations thereof. 
     
     
         31 . The method of  claim 17  further comprising mixing at least one performance additive selected from the group consisting of an anticorrosive agent or corrosion inhibitor, an extreme pressure additive, an antiwear agent, a pour point depressants, an antioxidant or oxidation inhibitor, a rust inhibitor, a metal deactivator, a dispersant, a demulsifier, a dye or colorant/chromophoric agent, a seal compatibility agent, a friction modifier, a viscosity modifier/improver, a viscosity index improver, and combinations thereof. 
     
     
         32 . The method of  claim 17  wherein, in the grease composition, the at least one base oil is present in an amount of from 50 to 95 weight percent, and the at least one polyurea thickener is present in an amount of from 0.5 to 20 weight percent, based on the total weight of the grease composition. 
     
     
         33 . A method for improving high temperature performance of a grease composition in a mechanical component lubricated with the grease composition, said method comprising using a grease composition comprising: at least one base oil; and at least one polyurea thickener; wherein said at least one polyurea thickener is prepared by reacting an isocyanate-terminated prepolymer with at least one amine under reaction conditions sufficient to prepare said at least one polyurea thickener; and wherein said isocyanate-terminated prepolymer is prepared by reacting a polyisocyanate with a polyol, at an NCO/OH equivalent ratio of 1.05:1 to 10:1, under reaction conditions sufficient to prepare said isocyanate-terminated prepolymer. 
     
     
         34 . The method of  claim 33  wherein said isocyanate-terminated prepolymer has an isocyanate content of 0.5 to 40 weight percent, based on the weight of the isocyanate-terminated prepolymer after reaction. 
     
     
         35 . The method of  claim 33  wherein the polyisocyanate is selected from the group consisting of 2,4-toluene diisocyanate (TDI); 2,6-toluene diisocyanate (TDI); 4,4′-diisocyanatodiphenylmethane (MDI); p-phenylene diisocyanate (PPDI); diphenyl-4,4′-diisocyanate; dibenzyl-4,4′-diisocyanate; stilbene-4,4′-diisocyanate; benzophenone-4,4′-diisocyanate; 1,3- and 1,4-xylene diisocyanate; and mixtures thereof. 
     
     
         36 . The method of  claim 33  wherein the polyisocyanate is selected from the group consisting of 1,6-hexamethylene diisocyanate (HDI); 1,3-cyclohexyl diisocyanate; 1,4-cyclohexyl diisocyanate (CHDI); saturated diphenylmethane diisocyanate H(12)MDI; bis{4-isocyanatocyclohexyl}methane; 4,4′-methylene dicyclohexyl diisocyanate; 4,4-methylene bis (dicyclohexyl)diisocyanate; methylene dicyclohexyl diisocyanate; methylene bis (4-cyclohexylene isocyanate); saturated methylene diphenyl diisocyanate; saturated methyl diphenyl diisocyanate; isophorone diisocyanate (IPDI); hexamethylene diisocyanate (HDI); 2,2,4-trimethyl-1,6-hexamethylene diisocyanate 2,4,4-trimethyl-1,6-hexamethylene diisocyanate; dodecamethylene diisocyanate; 1,4-diisocyanatocyclohexane; 1-isocyanato-3,3,5-trimethy-5-isocyanatomethylcyclohexane (IPDI); 2,4′- and/or 4,4′-diisocyanato-dicyclohexyl methane; 2,4-diisocyanato-diphenyl methane; 4,4′-diisocyanato-diphenyl methane; 2,4-diisocyanatotoluene; 2,6-diisocyanatotoluene; and mixtures of these isomers with their higher homologues. 
     
     
         37 . The method of  claim 33  wherein the polyisocyanate is selected from the group consisting of hexamethylene diisocyanate (HDI); 2,2,4-trimethyl-1,6-hexamethylene diisocyanates; 2,4,4-trimethyl-1,6-hexamethylene diisocyanate; dodecamethylene diisocyanate; 1,4-diisocyanatocyclohexane; 1-isocyanato-3,3,5-trimethy-5-isocyanatomethylcyclohexane; 2,4′-diisocyanato-dicyclohexyl methane; 4,4′-diisocyanato-dicyclohexyl methane; 2,4-diisocyanato-diphenyl methane; 4,4′-diisocyanato-diphenyl 2,4-diisocyanatotoluene; 2,6-diisocyanatotoluene; and any mixtures of these compounds and their higher homologues. 
     
     
         38 . The method of  claim 33  wherein the polyol is selected from the group consisting of polyester polyols, polycaprolactone polyols, and polyether polyols. 
     
     
         39 . The method of  claim 33  wherein the polyol is selected from the group consisting of polyester polyols, polycaprolactone polyols, polyether polyols, polyhydroxy polycarbonates, polyhydroxy polyacetals, polyhydroxy polyacrylates, polyhydroxy polyester amides and polyhydroxy polythioethers or mixtures thereof; wherein said polyols have at least two hydroxyl groups per molecule and have a hydroxyl group content of 0.5 to 20 weight percent. 
     
     
         40 . The method of  claim 33  wherein the polyol is selected from the group consisting of polyester polyols, polycaprolactone polyols, polyether polyols, polytetramethylene ether glycol, polyhydroxy polycarbonates, polyhydroxy polyacetals, polyhydroxy polyacrylates, polyhydroxy polyester amides and polyhydroxy polythioethers, or mixtures thereof. 
     
     
         41 . The method of  claim 33  wherein the isocyanate-terminated prepolymer is selected from the group consisting of TDI-ether, TDI-ester, TDI-lactone, MDI-ether, MDI-ester, MDI-lactone, H(12)MDI-ether, H(12)MDI-ester, H(12)MDI-lactone, HDI-ether, HDI-ester, HDI-lactone, IPDI-ether, IPDI-ester, IPDI-lactone, PPDI-ether, PPDI-ester, PPDI-lactone, and mixtures thereof. 
     
     
         42 . The method of  claim 33  wherein the amine is selected from the group consisting of pentylamine, hexylamine, heptylamine, octylamine, decylamine, dodecylamine, tetradecylamine, hexadecylamine, octadecylamine, eicosylamine, dodecenylamine, hexadecenylamine, octadecenylamine, octadecadienylamine, abietylamine, aniline, toluidine, naphthylamine, cumylamine, bomylamine, fenchylamine, tertiary butyl aniline, benzylamine, β-phenethylamine, stearylamine, laurylamine, palmitylamine, oleylamine, petroselinylamine, linoleylamine, linolenylamine, eleostearylamine, cyclohexylamine, primary tallow amine, ethylenediamine, propanediamine, butanediamine, hexanediamine, dodecanediamine, octanediamine, hexadecanediamine, cyclohexanediamine, cyclooctanediamine, phenylenediamine, tolylenediamine, xylylenediamine, dianiline methane, ditoluidinemethane, bis(aniline), bis(toluidine), piperazine, and mixtures thereof. 
     
     
         43 . The method of  claim 33  wherein, when said grease composition is used under high temperature conditions, high temperature performance in accordance with DIN 51821 (FAG FE9) is improved, as compared to high temperature performance achieved using a grease composition containing other than said polyurea thickener. 
     
     
         44 . The method of  claim 33  wherein structural stability and resistance to breaking down of said grease composition is improved when tested under high temperature conditions in accordance with DIN 51821 (FAG FE9), as compared to structural stability and resistance to breaking down achieved using a grease composition containing other than said polyurea thickener. 
     
     
         45 . The method of  claim 33  wherein, when said grease composition is tested using a Mini-Traction Machine (MTM) at 100° C., 1.0 GPa, 50% slide/roll ratio (SRR), and 3.0 m/s-0 m/s, coefficient of friction is improved, as compared to coefficient of friction achieved using a grease composition containing other than said polyurea thickener. 
     
     
         46 . The method of  claim 33  wherein the at least one base oil comprises a Group I, Group II, Group III, Group IV, Group V base oil, and combinations thereof. 
     
     
         47 . The method of  claim 33  further comprising at least one performance additive selected from the group consisting of an anticorrosive agent or corrosion inhibitor, an extreme pressure additive, an antiwear agent, a pour point depressants, an antioxidant or oxidation inhibitor, a rust inhibitor, a metal deactivator, a dispersant, a demulsifier, a dye or colorant/chromophoric agent, a seal compatibility agent, a friction modifier, a viscosity modifier/improver, a viscosity index improver, and combinations thereof. 
     
     
         48 . The method of  claim 33  wherein, in the grease composition, the at least one base oil is present in an amount of from 50 to 95 weight percent, and the at least one polyurea thickener is present in an amount of from 0.5 to 20 weight percent, based on the total weight of the grease composition.